import React, { Component } from 'react'

export default class Demo extends Component {
  state = { count: 0}

  add = () => {
    // 对象式的setState
    // 1.获取原来的count值
    // const { count } = this.state
    // 2.更新状态
    // this.setState({count: count+1}, ()=> {
    //   console.log(this.state.count)
    // })

    // 函数式的setState
    this.setState(state => ({count: state.count+1}))
  }

  render() {
    return (
      <div>
        <h1>当前求和为：{this.state.count}</h1>
        <button onClick={this.add}>点我+1</button>
      </div>
    )
  }
}
